Weird Residue on Trans fluid pan, Slipping at 2.5k

hello fellow aurora owners
I Droped my trans fluid pan to change the filters
and found some residue in the pan it was a lot looked like
shreded cork of some kind but hard,

so the trans seemed to be working fine
but in some hills i can notice some sort of slipping around 2.5k,
anything below or if i give it gas works fine

hope somebody can give info it will be greatelly apreciated

rafa